Injector for injecting auxiliary



April- 20, 1954 J. c. PORTER ETAL 2,675,788

INJECTOR FOR NJECTING AUXILIARY LIQUID TO THE FUEL OF INTERNAL-COMBUSTION ENGINES Filed me 18, 1948 2 Sheets-Sheat 1 gwowtow J C.PORTER W. B.ROTH

w, 4 ATTO NEYS- April 20, 1954 I .1. .PORTER ET AL I 2,675,788

INJECTOR FOR ECTING AUXILIARY L UID TO THE FUEL 0F INTERNAL-COMBUSTION E NES Filed June 18, 1948 4 I 2 Sheets-Sheet 2 J G. PORTER W..B.RO;TH

QQIATTOENEYS Patented Apr. 20, 1954 UNITED STATES PATENT OFFICE INJECTOR FOR INJECTING AUXILIARY LIQUID TO THE FUEL OF INTERNAL- COMBUSTION ENGINES James 0. Porter and William B. Roth, Peoria, 111., assignors to United States of America, as represented by the Secretary of Agriculture Application June 18, 1948, Serial No. 33,840

This application is made under the act of March 3, 1883, as amended by the act of April 30, 1928, and the invention herein described, if patented in any country, may be manufactured and used by or for the Government of the United States of America for governmental purposes throughout the world without the payment to us of any royalty thereon.

This invention relates to an injector for adding an auxiliary liquid such as water, alcohol, mixtures of water and alcohol, and so forth, to the fuel of an internal combustion engine which is subject to load and speed change, such as an engine of the automotive type, which is provided with an intake manifold and a carburetor having a venturi and a throttle valve, and has among its objects the provision of an injector which will automatically add the auxiliary liquid at the time the engine is operating under heavy load and at low speed, as at the time of rapid acceleration or a hard pull.

The use of high compression engines necessitates the addition of auxiliary liquids to the usual hydrocarbon fuel to prevent detonation if fuel efficiency is to be obtained, and it is during operation of the engine under heavy load and at low speed that the auxiliary liquid is most needed. At this time, the pressure within the intake manifold is increased, and the present invention utilizes the manifold pressure change automatically to control the injection of the auxiliary liquid.

In general, according to the invention, a reservoir for containing the auxiliary liquid is provided, and a pressure-responsive device operated by the change in pressure in the intake manifold controls the injector so as to inject the auxiliary liquid into the air intake of the usual type carburetor at a point ahead of the carburetor venturi and the throttle valve, in such manner that increased pressure in the manifold causes an increased rate of injection. This is accomplished by providing a valve outlet orifice communicating with the reservoir for free-flowing feed of the liquid therefrom and with the air intake of the carburetor at the point ahead of the venturi and the throttle valve. Since the liquid feeds freely from the valve outlet orifice into the air intake at a point not subject to significant pressure change, there results no substantial change in feed rate due to this structure. However, a movable valve gate assembly is provided for varying the feed rate by varying the effective size of the valve outlet orifice, and the pressure-responsive device moves the valve gate assembly such that the increased pressure in the manifold increases the effective size of the valve outlet orifice thus to increase the rate of fluid injection.

For a detail description of the invention, reference is made to the accompanying drawing, in which Figure 1 is a schematic showing of the association of the injector with the usual type engine;

Figure 2 is a top plan view of the auxiliary liquid reservoir with parts broken away for the purpose of illustration;

Figure 3 is a section on the line 33 of Figure 2 in scale slightly enlarged over that of Figure 2; and

Figure 4 is a section on the line i-i of Figure 2 in scale corresponding to that of Figure 3.

Referring to Figure l of the drawing, 1 i represents the block of a usual type automotive internal combustion engine, [2 the intake manifold, and [3 the carburetor having a fuel reservoir l4, fuel jet I5, venturi IE, throttle valve :3, and choke valve H3.

The injector of this invention is provided with an auxiliary liquid reservoir 28 which may be mounted in any convenient manner, the liquid being supplied from supply tank 2| through tube 22. Liquid is injected from reservoir 29 through injector tube 23 to the carburetor air intake at a point ahead of the venturi. A solenoid control valve 2G is placed in the line of injector tube 23 and connected through battery 25 and switch 26, so that opening of the switch closes the valve. Battery 25'may be the usual automobile storage battery, and switch 26 may be ganged with the ignition switch, so that when the ignition switch is turned off, valve 24 closes thus to prevent drainage of the auxiliary liquid when the engine is not running. Tube 28 communicates at one end with the intake manifold and at the other end with the pressure-responsive device, later described.

The auxiliary liquid reservoir 21) is provided with a removable cover 30 carrying a float valve 3| operated by a float 32 to admit liquid from the supply tank 2| through the tube 22, thus to maintain a constant liquid head in the reservoir. This structure may be of the usual design used in a carburetor to control the fuel level therein.

The injector is provided with an injector valve having a stationary valve seat 35, and movable valve gate assembly 36 such that as the injector valve is opened the liquid is injected into tube 23. Shoulder 31 of the valve rod assembly rests in contact with valve seat 35 in the shutoff position, shown by the solid lines of Figure 3. The

open position is shown by the corresponding broken lines of the same figure.

An embossment 38 is integrally cast with the auxiliary liquid reservoir, and is bored to provide a cylinder in which a piston 39 is movable. A counterboring 40 communicates with the lower end of the cylinder and with the tube 23, thus to provide means for communicating the lower end of the cylinder with the intake manifold, such that as the pressure increases in the manifold, the increased pressure operates against the lower end area of the piston, as .viewed in Figure 3. The piston is biased with a spring ll so adjusted that at high speeds and low load of the engine, with consequent low manifold pressure, the piston rests in its lower position, and is raised with increased manifold pressure, thus responding to manifold pressure changes.

The piston is attached to the valve gate assembly in such manner that movement of the piston in the cylinder due to increased pressure in the manifold opens the valve. This is accomplished by means of a bracket 32 rigidly attached to the piston at one end thereof as by pin it integral with the piston and press fitted in an aperture in the bracket, the other end of the bracket being provided with a slot slidably engaging bar G l having a head 45 to stop extreme upward movement of the piston and bracket, the valve gate assembly 35 being carried upward and downward with movement of the bracket and piston by being fixedly attached to the bracket as by means of a press fit in an aperture of the bracket.

The flow of amiliary liquid further con trolled by a needle valve pin ii, made adjustable relative to the valve outlet orifice it situated beneath the seat 35, and to the position of the piston and bracket. This adjustment is obtained by providing the exterior tubular casing 36 and the needl valve pin ll threaded into the casing, as shown at 50, the needle valve pin being provided at its upper end with a knurled thumb knob i. This needle valve pin is movable in the valve outlet orifice s8 and when the needle valve pin has been properly adjusted relative to the orifice, it is locked in adjusted position with the lock nut 52 clamping a compressible washer 53 against the pin.

Rotation of the needle valve pin results in raising or lowering it relative to orifice 1B. This varies the eifective size of the orifice for a given position of the casing 26 or the piston. Thus the over all rate of injection of the auxiliary liquid relative to the manifold pressure may be varied.

In operation of the injector, whil the engine is running under light load, the pressure within the manifold is lowered, and the piston rides in full line position shown in Figure 3, thus maintaining the valve shoulder 3? closed on the seat 35. Opening of the carburetor throttle valve with the engine at low speed, as in th case of climbing a hill or for rapid acceleration, increases the pressure in the manifold. This results in an increased pressure on the lower end area of the piston, causing it to rise, the extreme higher position being shown in dotted lines in Figure 3. This opens the injector valve and allows the auxiliary liquid to be injected into the tube 23 and into the carburetor air intake, at a point ahead of the venturi, the rate of injection of the auxiliary liquid depending on the position of the piston and upon the position of the needle .valve pin relative to the jet orifice 38. The pressure in the air intake ahead of the venturi is not prop er.

materially affected by load or speed conditions, and since a constant head is maintained on the auxiliary liquid, the feeding thereof into the fuel is substantially completely controlled by the intake manifold pressure. The result is that the auxiliary liquid is fed to the fuel at the times and rate needed, and it is possible to obtain a high fuel eificiency with this arrangement.

The device shown in the drawings may be varied considerably. For example, spring 40 of Figure 3 may be placed above the piston or even outside the cover 3%. This may be desirable when the auxiliary liquid employed would tend to corrode the spring. This may be accomplished by extending pin 33 through a hole in cover 30 and attaching the spring suitably and in known manner. Furthermore the needle valve and jet orifice may be separate from the injector valve In this variation seat 35 and shoulder of the valve rod function to open and close with the action of the piston 38, no intermediate adjustment being possible by the piston. Tube 23 then contains a conventional needle valve adjustment situated at a convenient point between the reservoir 20 and the point of injection into the carburetor intake.

As a detail example, an injector was provided for a well-known type of automobile engine which operated with manifold pressures of from 8 to 14.7 lbs. per sq. in. (absolute), and the pressures at which it was desired to inject the auxiliary liquid at the increased rate was from 11.2 to 14.7 lbs. per sq. in. (absolute). In this case, a piston having a bottom end area, or effective area against which th manifold pressure reacted, of 0.20 square inch was used. The total weight of the assembly of the piston, bracket and needle valve rod was 0.10 lb.. The play of the piston between its lowermost position and extreme upper position, which corresponds to the full range or" opening of the injector valve, was 0.312 inch. Spring 40 was selected to give a compression force of from 0.75 to 0.25 lb., depending on the position of the piston from the lowermost to the extreme upper. Variation in these dimensions may be made so long as the pressure-responsive device operates to open and close the injector valve over the desired range of manifold pressures.

Having thus described the invention, what is claimed is: r

1. The combination of an internal combustion engin which is subject to load and speed change and which is provided with an intake manifold and a carburetor having a venturi and a throttle valve, of an injector for adding an auxiliary liquid to the engine fuel comprisingareservoir for containing the auxiliary liquid, a valve outlet orifice communicating with the reservoir for free flowing feed of the liquid therefrom and with the air intake of the carburetor at a point ahead of the venturi and the throttle valve,-a movable valve gate assembly for varying the rate of inga te assembly such that increased pressure in the manifold increases the efiective size of the valve outlet orifice thus to increase the rate of fluid injection. j

2. The combination of claim 1 characterized in that the pressure-responsive device comprises a cylinder one end-of which cornmun-ic ates with the intake manifold, and a piston movable in the cylinder, the valve gate assembly being attached to the piston so as to move therewith.

3. The combination of claim 2 characterized in that the valve gate assembly comprises a needle valve pin movable in the outlet orifice and a tubular casing in which the needle valv pin is threaded, the tubular casing being attached to the piston, whereby the needle valve pin is adjustable relative to the valve outlet orifice for a given position of the piston.

4. The combination of claim 1 characterized in that the valve gate assembly comprises a needle valve pin movable in the valve outlet orifice and a tubular casing in which the needle valve pin is threaded, the tubular casing being attached to move with the pressure-responsive device, whereby the needle valve pin is adjustable relative to the valve outlet orifice for a given position of the tubular casing.

5. An injector for adding an auxiliary liquid to the feed of an internal combustion engine provided with an intake manifold and a carburetor having a venturi and a throttle valve, comprising a reservoir for containing the auxiliary liquid, a valve outlet orifice communicating with the reservoir for free-flowing feed of the liquid therefrom and having means for communicating with the air intake of the carburetor at a point ahead of the venturi and the throttle valve, a movable valve gate assembly for varying the rate of injection of the liquid from the reservoir, through the orifice, and into the air intake by varying the efiective size of the valve outlet orifice, and a pressure-responsive device for operation by change in pressure in the intake manifold to move the valve gate assembly such that increased pressure in the manifold increases the effective size of the valve outlet orifice thus to increase the rate of fluid injection.

6. The injector of claim 5 characterized in that the pressure-responsive device comprises a cylinder one end of which has means for communicating with the intake manifold, and a piston movable in the cylinder, the valve gate assembly being attached to the piston so as to move therewith.

'7. The injector of claim 6 characterized in that the valve gate assembly comprises a needle valve pin movable in the outlet orifice and a tubular casing in which the needle valve pin is threaded, the tubular casing being attached to the piston, whereby the needle valve pin is adjustable relative to the valve outlet orifice for a given position of the piston.

8. The injector of claim 5 characterized in that the valve gate assembly comprises a needle valve pin movable in the valve outlet orifice and a tubular casing in which the needle valve pin is threaded, the tubular casing being attached to move with the pressure-responsive device,

-' whereby the needle valve pin is adjustable relative to the valve outlet orifice for a given position of the tubular casing.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,622,701 Brewer Mar. 29, 1927 1,623,053 Howard et a1. Apr. 5, 1927 1,889,584 Zimmerer Nov. 29, 1932 2,460,700 Lyons Feb. 1, 1949 

